Forming tube for glass fibers



United States Patent [56] References Cited UNITED STATES PATENTS 1/1969 3,451,433 6/1969 Cunningham et a1. 3,455,521

[72] Inventor McCleery B. Cunningham, l-lartsvllle, South Carolina 3,424,204 138/144 138/ I44 7/1969 Cunningham et al......... 242/1 18.32 Primary Examiner-Henry S. Jaudon Attorney-C. Gordon McBride 8, n u m m a.mC dh mrt 08n- CC M mm a w o mSo l 9 ea o m fl oo m m. u r mmn 6 o 7. MDSH8 0 08 N m m L 8 wmv m Ha AFPA 1.1.1.] 253 2247 .l:l1:l.

[54] FORMING TUBE FOR GLASS FIBERS 5 Claims, 5 Drawing Figs.

ABSTRACT: A spirally wound, collapsible forming tube for glass fibers including at least one in ner paper ply, an intera1 impregnated with an mediate ply of woven textile materi F161 9/16 elastomeric material, and resin impregnated outer paper ply l38/l29, having a hard, smooth external winding surface for glass fibers.

[51] Int.Cl............... [50] FieldofSearch............................................

PATENTED DEB 8197B SHEET 1 [IF 2 INVENTOR MC CLEERY B. CUNNINGHAM AT TORN EY PATENTED DEL 8 19m SHEET 2 UF 2 INVENTOR M CLEERY B. CUNNINGHAM aid AT TORNEY FORMING TUBE FOR GLASS FIBERS This invention relates totexti le carriers and more particularly to a carrier or forming tube" for use in the winding of freshly spun glass filament or fibers.

In the spinning of glass fibers to be processed into textile material such as yarn and the like, glass in a molten state is drawn through small openings or orifices in a plate commonly referred to as a spinneret into the fonn of continuous filaments which solidify upon contact with the air. These continuously drawn filameritsare'wound onto a tubular carrier in the form of a flexible cylindrical sleeve which is generally referred to as a"forming tube. Ina glass fiber spinning operation, this forming tube is slipped onto a spindle or the like which is rotated at very high speeds, frequently around 8,000 to 10,000

r.p.m. and up, and the glass filaments are drawn from the spinneret and wound on the tube at a relatively high linear speed generally 10,000 to 12,000 feet per minute and more. These and the rugged conditionsofuse to which it is subjected, these tubes must meet rigid standards and preferably should be of a suitable design and material so as not only to be expensive in initial cost but to be capable of repeated, use. Furthermore, these formingtubes must be provided with extemalsurface characteristics specifically suitable for the glass fiber winding and unwinding operations for which they are used. In general, it can be said that such tubes are requiredto have a relatively smooth peripheral surface to permit the glass fibers to be readily unwound from the tube and at the same time this peripheral surface should be sufficiently rough so that satisfactory winding of the fibers on the tube may be accomplished. In

addition, these tubesshould also be of light weight to avoid deformation by centrifugal force which at the speeds referred to above is Of a substantialmagnitude. Furthermore, these forming tubes should be highly resistant to compression by the fibers wound tightly on the tube so that the tube maintains its shape after removal from the spindle and the tubes should have sufficient flexibility and elasticity to permit their ready removal from the wound package of glass fibers when the tube istobe reused.

Two commonly employed materialsin use today for making such forming tubes are plain paper or paperboard and plastic such as polyethylene both of which have objectionable features. Although a forming tube composed solely of ordinary paperboard generally performs satisfactory the, first time it is used, its inherent lack of strength and lack of flexibility causes it to deteriorate rapidly when reused. It is thought that the rapid deterioration of such paper forming tubes occurs primarily as a result of the breaking of the cellulosic fibers in the tube resulting from the bending and folding to which such paper tubes are subjected. Therefore, forming tubes of fibrous material such as paper or paperboard are generally discarded after a few uses or even after a single use adding considerably to glass fiber manufacturing costs even though the initial cost of such paper is low. Forming tubes of plastic have also been used with some success but the severe stresses to.which plastic forming tubes are subjected frequently causes plastic tubes to disintegrate or explode during use primarily as a result of centrifugal forcen'ot only creating a hazard but, as a result of forming tube of great strength and flexibility capable of repeated use.

. A further'object of this invention is to provide a new and novel nonrigid forming tube for winding glass fibers which is low in initial cost, which is easily manufactured on conventional winding apparatus, and which contains a highly suitable winding surface for glass fibers.

Still another object of this invention is to provide anew and which utilizes a combination of materials to prevent spreading of weakened localized areas on the tube such as result from thin spots, tears or the like. I

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings.

In general, the objects of this invention and other related objects are accomplished by spirally winding at least one strip of fibrous material such as paper and winding thereon a ply of woven textile material such as cloth impregnated with an elastomeric material. A strip of resin impregnated paper is wound spirally over the woundstrip of textile material so as to provide a tube having a paper inner ply, an intermediate ply of cloth impregnated with'the elastomeric material and a resin impregnated outer paper ply. A spiral wrap of release material is also preferably wound over the resin impregnated outer ply which is removed after the resinous material is cured to provide a hard, smooth'externalwinding surface on the tube for glass fibers. r i

The novel features which are believed to be characteristic of the invention are set forth with particularity in the appended claims. The inventionitself, however, both as to its organization and method of operation may be best understood by reference to the following description taken in conjunction with the accompanying drawing in which:

FIG. 1 is a diagrammatic illustration of tube winding ap paratus for winding theforming tube of the invention;

FIG. 2 is a sectional view taken substantially along line 2-2 of FIG. 1 in the direction of the arrows;

FIG. 3 is an enlarged perspectiveview' of the tube of the invention wound withthe apparatus of FIG. 1;

FIG. 4 is an enlarged sectional view taken substantially along line 4-4 of FIG. 3 in the direction of the arrows; and

FIG. 5 is a sectional view similar to -FIG. 4 showing the forming tube of the invention in a collapsed condition.

Referring now tothe drawings and to FIG. 1 in particular,

there is shown diagrammatically a typical spiral tube winding apparatus by means which the winding of the forming tube of the invention iscarried out. As previously stated, the forming tube of the invention, which is shown in section in a collapsed condition and designated generally by the numeral 11 in FIG. 5, is of the type which is particularly suitable for use in the winding of freshly spun glass filaments or fibers drawn from the spinneret of a glass furnace (not shown). However, the tube 11 of the invention may also be employed in other glass fiber manufacturing operations involving glass fiber windin and takeoff procedures. i i

As generally illustrative of the method of winding the forming tube 11 of the invention, the conventional spiral tube winding apparatus of FIG. 1 is designated generally by the numeral 12. This spiral tube winding apparatus 12 is of the conventional type and is shown carrying out of a winding opera 1 tion by means of whicha continuous tube T advanced in the direction of the arrow I is produced. The tube T is cut into 11 of the invention cutting the continuously wound tube T into uniform sections of a selected length. i

In the winding of the continuous tube T, at least one strip 21 of paper unwound from a supply roll 22 is first wound on the tube making mandrel 14. Preferably, two such paper strips are employed and accordingly a second paper strip 23 unwound from a supply roll 24 is wound in overlying staggered relationthe strip 23 and the applicator roll 26 is maintained by advancing the strip 23u'nder guide rollers 28, 29also suitably..sup ported to rotation on the receptacle 27. The paper strips 21, 23 are preferably each woundwith the edges of adjacent convvolutioiisin an abutting relationship although, it should be understood, that the adjacent edges of ,the strips 21, 23 may be overlapped if desired. As shown in FIG. 1, the ply formed by strip 21 is provided witha spiral butt seam 21a and the ply formed by strip 23 is provided witha spiral butt seam 23a.

As the spirally wound plies formed by paper strips 21, 23 advance along themandrel l4,down-from the belt 16, a strip of woven textile material32 impregnatedwithan elastomeric material is spirally woundin overlying relationship with wound paper ply 23 to form a spirally wound intermediate ply. Any suitable woven textile material may be employed for the ply 32 and in one embodiment, a loosely woven textile material referred to in the textile industry as osnaburg cloth provides the novel results obtained with the, forming tube of the invention. Preferably, the impregnated cloth strip 32 is wound with the edges of adjacent convolutions in overlapping relationship.

"The strip 32 is woventextile material is unwound from a supply roll 33 and is impregnated with an elastomeric material in liquid form by advancing the strip.3 2 through a receptacle 34 containing an impregnating bath 36 of elastomeric material as shown best inIFlG, 2.,Any suitable elastomeric material which remains permanently stretchable" or frubbery" after curing may be used as the impregnating medium inthe. bath 36. For instance, polymeric material such as polyvinyl chloride, polyvinyl acetate etc may be employed which is of a type available initially in a liquid form for impregnation and whichafter curing remains in a permanently elastomeric or rubbery state. The elastomeric material used may be of the type curable by any wellknowneuring process such as air curing, curing by solvent evaporation or the like.

Guide rollers 37-40 are suitably positioned as shown in FIG. 2 adjacent the receptacle34 so that the strip 32 is immersed in the elastomeric material bath 36 and subsequently removed for winding onto the paper ply 23. An outer ply 411,0ffibrous material such as paperunwound from a supply roll 421s impregnated with a suitable resinous material is then spirally wound in overlying relationshipwith the wound impregnated clothply 3241s shown in FIGS, 1, 3. The paper strip 41 is impregnated by advancing the strip 41 through a receptacle43 containing an impregnating resinbath Preferably,,the resinous material of the bath 44 is an acrylic resin which is providedin the form of an aqueous emulsion. The curing of thisresinous material 44 may therefore be accomplished by the'evaporation of the water vehicle from the acrylic resin and waterrnixture.

Suitable guide rollersareprovided in association with the receptacle similar. to :the arrangement for the receptacle 34 as shown in FIG. 2,whi,ch. include guide rollers 46, 47 and 48 as shown in F l6. 1. The paper strip 41 is therefore immersed in the resinous ernulsionbath44 and subsequently removed for winding spirally in overlapping staggered relationship with the impregnated cloth ply 32.

ln order to provideahard, uniformly smooth, slick surface on the impregnated paper ply 41 after the resin is cured, a wrapping ply 51 of fsmooth, slick, release material such as polyethylene, cellophane or thelike is unwound from asupply roll 52 and' spirally wrappedias shown in FIGS. 1, 3 in overlying relationship with the impregnatedouter paper ply 41. The

ply 5 1 is. preferablyl wrapped withthe edges of adjacent convolutions in overlapping relationship as shown to form an outer spiral seam 51a completely coveringthe underlying resin impregnated plyfil. lar'eferably the impregnated paper strip 41 is wound with the edges adjacent convolutions in overlapping relationship as shown best in FIG. 3 to form an outer spiral scam 41a. i

With the use of release material for the ply 51, there is no adherence of the release material ply 51 to the resinous material with which the paper ply 41. is impregnated and ply 51 is tightly wound in the spiral winding operation with FIG. 1 with the underlying ply 41 to form the T. The tight engage- .ment'of wrapping ply 51 with the impregnated paper ply 41 not only confines the'resin within ply 41 but produces a substantially complete engagement'between thesurfaces of the two plies. As the continuously formed tube T moves in the tube 7 isthen carried out so that the .water vehicle in the resinwater mixture in the tube outeriply4l will be evaporated and the resin with which the ply 41 is impregnated will set or cure permanently. Using an aqueous acrylic resin mixture for impregnation of the tube ply 41 permits the curing to be accomplished under normal room temperature over relatively short periods of time. However, if it is desired to shorten the curing time by the application of heat, meanssuch as an oven canbe I utilized. The elastomeric material with which the cloth ply 32 is impregnated is also permitted to cure into a rubbery state having a degree of elasticity so as to permit stretching when the cloth ply is deformed. After curing, the wrapping ply 51 of release material is then unwound from each cured tube section and discarded. When the .wrapping ply 51 has been removed, it will be noted that the resin impregnated underlying paper ply 41 has been compressed and.smoothed soas'to provide a hard, relatively smooth slick outer surface. This shiny,-,slick outer surface on the resulting tube-l1 is, in effect,

. a reproduction of the slick surface of the polyethylene ply 51 so that the entire outer or winding surface of the tube '11 is surface having a smooth, slick appearance and feel. The cured tube sections aresthen cut into a plurality of short lengths,

preferably lengths of approximately 8 inches to provide forming tubes 11 of a length suitable for use in a glass fiber winding and unwinding. operation.

1 It can beseen that the forming tube 11 of the invention is not only characterized by high strength and durability so asv to be capable of repeated use with a minimum of deterioration but it may be easily removed from a package of glass fibers wound thereon by collapsing the tube 11. The outstanding feature ofthe-tube of the invention are the new and unexpected results obtained by the novel combination of various materials .from which the tube is formed. As is well known, rapid deterioration and/ordestruction of forming tubes of the type presently available for the purposes described herein occur primarilyfrom aweakening or splitting ofthe endedges of the tube which areas spread rapidly throughout the sleeve resulting in ultimate tube destructiomAs a result of the-elastomeric material with which the cloth ply32 is impregnated, stress applied to the end portions of the tube of the invention is .ab-

sorbedas the elastomeric material stretches to permit sliding movement and resultant bunching up" of the threadsfrom which the woven cloth is formed thereby gradually absorbing and ultimately resisting any deterioration of the tube wall.-At the same time, the paper plies on the opposite sides of the impregnated cloth ply 32 retainsthe impregnated cloth ply sandwiched therebetween forming a laminated structure in which:

the various laminations in mutually reinforcing relationship.

At the same time, the resin impregnated outer-paper ply has ,a smooth, slick surface ideally suitable for the winding of glass.

fibers.

While there has been. described what at present is considered tobe the preferred embodiment of theinvention, .it

will be understood by those skilled in theartthat various changes and'modificationsmay bemade therein without departing from the invention.

1 claim:

l. A nonrigid forming tube for glass fibers comprising, in combination, at least one spirally wound inner ply of paper, a spirally wound intermediate ply of woven textile material impregnated with an elastomeric material and a spirally wound outer ply of paper, a said paper plies and said ply of textile material having a thickness and composition for permitting said forming tube to flex readily and collapse longitudinally for removal of the tube from apackage of glass fibers wound thereon.

2. A nonrigid forming tube in accordance with claim 1 wherein said spirally wound outer ply is impregnated with a resinous material. 

